7 March 2010

I find out the coolest things by working in television.  Here’s one about a “bird” I don’t normally discuss.

Last week I received an email from PBS Engineering with a list of dates and times when PBS stations will experience satellite interference from the Sun on the AMC-21 satellite. 

Why?

PBS uses AMC-21 to send programming to the stations.  PBS beams it up and each station has a dish to pull it down for pre-recording or broadcast. 

AMC-21 is a geosynchronous satellite so it orbits the earth at the same speed the ground is moving.  From our perspective on earth, the satellite never appears to move so we can point our dishes to just one place and never have to adjust them.  Unfortunately the sun reaches that same sweet spot twice a year.

In the weeks near the equinox the sun gets in the way.  For about 15 minutes per day the sun’s path is directly behind (in line with) the satellite.  The sun emits a lot of radio waves and in this position it confuses our dish receivers.  The dates and times of the interference depend on your location on earth.  It’s worse in heavy sun spot years.  This year “there should be minimal Ku-Band sun outage disruptions due to the low level of solar activity” according to PBS. 

For WQED most of the interference happened earlier this week.  Our last episode will be today from 3:45pm to 3:59pm but you’ll never notice it on the air.  We correct for it in our engineering department. 

The sun is on the move (actually the earth is traveling around it) so this phenomenon will stop soon.  To read more about it, see this informative article from Australia’s IPS Radio and Space Services.

And yes, some people call satellites “birds.”  It’s confusing!

(artists rendition of the AMC-21 satellite from Orbital Sciences Corporation)

It’s the last day of the shortest month of the year.  Thank heaven!  

As of this morning the first 27 days of February produced 48.3 inches of snowfall.  This is already the snowiest month ever recorded in Pittsburgh and if any accumulates today the record will go higher.  Today’s forecast calls for snow.  Less than an inch.  Hmmmm.

Until this month I was always happy to see snow.  Perhaps my short respite in Florida lowered my tolerance.  Perhaps more than four feet of it turned me off.

I still think snow is beautiful but I’m weary of it.

(photo by Marcy Cunkelman)

The weatherman says it’s going to snow 6 to 10 more inches in the next two days with gusty winds and blowing, drifting snow.  Oh no!

Where will we put more snow?  Will the wind break the trees that survived until now?  Will the power stay on?  Will my street ever get plowed?  When will garbage collection resume?  When will the 56U bus, the one I take to work, start to run again?  Will any buses be running?  Will I be able to walk in the street to get to work without being killed?

I’m losing my resilience. 

It was pretty, but enough already!

(Snow in Greenfield, 8:00am Saturday Feb 6, 2010, photo by Kate St. John)

Remember last month when I showed you Marcy’s orange ruler measuring almost 10 inches of snow?

This morning I had to get out the yardstick.

At 8:00am there were nearly 21 inches in my backyard.  I left the ruler out there and it now reads 21.75 inches.

And it’s still snowing heavily.

I’ll try to take more pictures today if I can get outdoors, but it’ll be a challenge because my boots aren’t that high!  Meanwhile you can click on the yardstick to see what our neighborhood looked like from the street at 8:00am.

(Sorry for the poor image quality; these are from my cell phone.)

(photo by Kate St. John)

My gosh it’s cold! 

Friday morning it was 6^o F.  Yesterday morning it was 12^o.  This morning it’s back down to 7^o. 

Not only is it cold but we’re missing the deep snow cover that provides insulation for plant roots and ground-dwellers.  The mid-January thaw and subsequent freeze will be very hard on the plants and animals living at the northern edge of their hardiness zone.  The good news is that it’s also hard on bugs, so maybe we’ll have fewer pests next spring.

When will it get warmer?  The weather forecast says it’ll be 37^o on Thursday. 

In and out of the deep freeze again.

(photo by Dianne Machesney, taken before the mid-January thaw)

Despite the continuing cold and snow, the battle to get in and out of winter coats and boots, and the difficulties of walking and driving in snowy weather, winter took a turn for the better in the past few days.

I was beginning to get bored by it but I perked up when I read some local sightings on PABIRDS and encountered some surprises on my own:

• Last Friday Steve Gosser saw a peregrine falcon attack a juvenile bald eagle who was flying over the Allegheny River.  This was in downtown Pittsburgh at the 7th Street Bridge!
• Yesterday morning Dorothy and E2, the Cathedral of Learning peregrines, met for breakfast on their favorite dining ledge on the northeast corner of the 30th floor.   It looked to me like he’d brought her food.  Courtship!
• On Sunday I drove along the Ohio and Beaver Rivers and saw two bald eagles and two ravens near Dashields Dam, plus another eagle along the Beaver River.  If you’re looking for eagles, just a few moments at Dashields ought to turn one up.
• Yesterday I had a pleasant surprise when I found a white-throated sparrow in Oakland near Craig Street.
• And everyone knows I’m interested in the crow report.  Last evening a co-worker called me as she drove over the 31st Street Bridge to tell me the Allegheny River is frozen over and the crows were flying in and landing on the ice.  So that’s where they’ve gone.  Woo hoo!

The weather report says we’ll have above freezing temperatures starting tomorrow.  If it melts all at once the floods will provide more excitement than we want.  (!)

(photo of tulip tree seed pods by Marcy Cunkelman)